The carboxy-terminal domain of the a subunit (aCTD) recognizes the Up-element (where present), whereas s regions 2 and 4 recognize the –10 and –35 regions

TLS Online TPP Program

#Id: 9043

#Unit 4. Cell Communication and Cell Signaling

Switching mechanism of monomeric G proteins 

“On” state, switch I and switch II, are bound to the terminal γ phosphate of GTP with the backbone amide groups of conserved T & G.

TLS Online TPP Program

#Id: 9044

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9045

#Unit 4. Cell Communication and Cell Signaling

Switching mechanism of monomeric G proteins 

“Off” state, Removal of the γ phosphate by GTPase-catalyzed hydrolysis causes switch I and switch II to relax into a different conformation

TLS Online TPP Program

#Id: 9046

#Unit 4. Cell Communication and Cell Signaling

Monomeric G proteins, including Ras and various Ras-like proteins, do not directly bind to receptors but act as intermediate proteins in signal transduction pathways.

TLS Online TPP Program

#Id: 9047

#Unit 4. Cell Communication and Cell Signaling

Monomeric G proteins are evolutionarily ancient, as evidenced by their widespread functions examples include: 

eIF2

EF1α and EF2

Ran

Sar

Rab

Rho, Rac, and Cdc42

TLS Online TPP Program

#Id: 9048

#Unit 4. Cell Communication and Cell Signaling

All G protein–coupled receptors contain seven transmembrane α-helical regions (H1–H7). In many GPCRs a short α helix H8 lies parallel to the membrane surface, and a covalently bound palmitic acid group